Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
D-galactose-binding (or chemoreceptor) protein of Escherichia coli serves as an initial component for both chemotaxis towards galactose and glucose and high-affinity active transport of the two sugars. Well-refined x-ray structures of the liganded forms of the wild-type and a mutant protein isolated from a strain defe…
A diluted classical spin chain with competing exchange interactions is studied by the transfer matrix method. It is found that a nonmagnetic impurity perturbs the helical spin structure and leads to a new local equilibrium spin complex. Numerical results for the correlation functions are discussed in connection with t…
Neutron diffraction studies on Fe0.8M0.2Sn (M : Mn, Co) over a temperature range 400 K to 20 K show spin reorientation features in the Mn substituted compounds, while in the Co substituted one the spins are locked along the c direction even down to 20 K.
Porphyrins are known to be accumulated and retained by tumours and atherosclerotic plaques. This property has been used for a new therapeutic approach called photodynamic therapy. In this study we assessed whether the presence of arterial hypertension could modify porphyrin turnover in the vascular wall. At various ti…
Specific heat and Raman scattering were measured on sintered samples with x around 0.5, which show a sharp metal-to-insulator transition (MIT) with increasing temperature. Specific heat below MIT can be well expressed by C = γT + βT3 + δT3 ln T with parameters comparable to those of TiBe2. Spectrum of Raman scattering…
Presents experimental results on the electrode-fall of local discharge on electrolytic surfaces, which simulate the surfaces of wet polluted insulators. A rod-plane electrode system with the electrolyte layer on the plane electrode was used. This electrode system was set in a Pyrex glass chamber. The air pressure in t…
Compounds of the form RCo4-xFexB are ferromagnetic for R = Pr, Nd, Sm (x < 2) and ferrimagnetic for R = Er, Tm, Lu, with Tc ∼ 500 - 600 K. 57Fe Mössbauer spectra yield their magnetization directions, which depend both on the R.E. anisotropy and on the transition metal anisotropy.
The electrical resistivity and magnetic susceptibility of amorphous ${\mathrm{Cr}}_{\mathrm{x}}$${\mathrm{Ge}}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$ alloys (0\ensuremath{\le}x\ensuremath{\le}0.65) prepared by means of the flash-evaporation method were investigated in relation to the amorphous structure. The partial pa…
A number of NH4HSeO4-NH4HSO4 mixed crystals have been grown. The system exhibits limited solubility in the solid state. The limiting solid solutions correspond to x = 0.32 and 0.67 (x - molar fraction of NH4HSO4). Based on X-ray diffraction, Differential Thermal Analysis and dielectric studies, the phase diagram has b…
Abstract The present paper is concerned with a crystallization process which occurs in the interior of a polymer melt, when its boundary (mold wall etc.) is suddenly quenched. As polymer melts are prone to supercooling, dispersed nucleation can take place at a distance from the boundary, if the local temperature has b…
Magnetic characteristics of NdCo2Si2 have been studied by magnetic and neutron diffraction measurements using a single crystal. Three antiferromagnetic phases were found below 32 K. A simple collinear antiferromagnetic phase is stable in the range 0-15 K where a metamagnetic process is observed. Square-wave structures…
The kinetics of thermal decomposition of aluminum sulfate was studied by dynamic and isothermal thermogravimetry. The nature of the solid phases was further examined by powder x-ray diffraction. Various kinetic models such as nucleation, phase boundary movement, diffusion and the homogeneous reaction were tested. Effe…
Abstract The crystallization behavior of polyetheretherketone (PEEK) was investigated by differential scanning calorimetry (DSC). The glass transition temperature of PEEK shifts to higher temperatures with an increase in crystallinity. Heat‐treated PEEK showed double peaks in their DSC curves, which is a characteristi…
High spin states of $^{189}\mathrm{Tl}$ have been populated through the fusion-evaporation reactions $^{169}[^{24}$Mg(125 MeV),4n], $^{165}[^{28}$Si(140 MeV),4n], and $^{175}[^{20}$Ne(128 MeV),6n] and its subsequent decay studied by in-beam \ensuremath{\gamma}-ray spectroscopy techniques. Among the firmly established…
Magnetic and crystallographic measurements were made for Co2-xFexMnM (M Si, Ge, Sn and Ga) and Co2-xMnxSi. In Co2MnM, the magnetic moment (µP) in the paramagnetic temperature region is generally much smaller than the ferromagnetic moment (µF) at T = 0 K, which implies that the Co-moment disappears above TC. The other…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTVibrational analysis of sublevel phosphorescence spectra of potassium tetrakis(.mu.-diphosphonato)diplatinate(II): mechanism of radiative transition for the electronically forbidden A1u spectrumTakeshi Ikeyama, Seiichi Yamamoto, and Toru AzumiCite this: J. Phys. Chem. 1988,…
Abstract Chlorite belonging to subfamily C, vermiculite 2 M B -VII-meso, talc and a monoclinic amphibole were identified in rocks from a contact zone between highly tectonized granite and serpentinite at Jordanów, Lower Silesia, Poland. K-saturated vermiculite readily produced a phlogopite-like structure 1 M -I (3T A…
Se estudia la composición específica del fitoplancton de 16 lagunas de alta montaNa de Sierra Nevada. Las lagunas estudiadas se encuentran situadas sobre sustrato silíceo y con una altitud comprendida entre los 2.500 y los 3.100 m. Presentan un período libre de hielo que oscila entre 5 y 6 meses, normalmente de ju…
Abstract Novel Ni-hectorite inorganic complexes were synthesized hydrothermally from homogeneous Ni–Si hydrous oxide gel at 200 °C for 2 h. Dispersed slurries of these complexes showed rheological properties similar to those of natural smectites and, on heating, formed porous materials characterized by large specific…
Abstract The IR and Raman spectra of various saturated solutions of 4‐nitropyridine N ‐oxide (NPO) and NPO‐ d 4 were recorded in the range 4000–350 cm −1 . They were assigned according to previous results for the crystal. A strong Fermi resonance is observed in the ν as (NO 2 ) region for solutions of NPO in CCI 4 , C…